1. Field of the Invention
This invention relates to document imprinters, especially for labels, tickets, tags, and the like. More particularly, it has to do with the setting means for the printing wheels of such an imprinter.
2. Description of the Prior Art
Prior art document imprinters include a rotary printing unit having several banks, usually three, of printing wheels which successively print on different lines of a label web or the like. Such imprinters customarily include setting mechanisms, one for each bank of printing wheels, whereby the operator can change the printing setting of each bank of wheels. In prior art machines, the viewing windows of the setting mechanism have been so arranged that the operator can effectively see at one time only the viewing window for one bank of printing wheels. Therefore, to set all three banks of wheels the operator will have to manually rotate the printing unit back and forth to successively position the other printing windows so that she can see them. This rocking movement can result in label wastage, unintended printing, and erroneous printing. The foregoing defects are objectionable enough when the printer is used for conventional visually readable printing, but cannot be tolerated when the invention is to be used for the printing of OCR characters, i.e., characters which are visually readable and also automatically readable by optical character recognition equipment. They will result in reading errors.